Nancy Dickson, sister of Governor Seriake Dickson, was abducted from her shop along with her sales assistant in the state capital Yenagoa on Saturday, police spokesman Asinim Butswat said in a statement.
“Four unknown gunmen in an ash-coloured Lexus jeep, tailed Nancy Keme Dickson, 26 years, to her shop at Okaka road, Yenagoa, and abducted her and her sales girl,” he said.
Police had launched a man-hunt for the kidnappers.
The abduction comes as her brother seeks re-election in Bayelsa, the homestate of ex-president Goodluck Jonathan who lost the March election to President Muhammadu Buhari and his All Progressives Congress (APC).
But the December 5 vote in Bayelsa state was declared inconclusive because of violence and electoral irregularities in the southern Ijaw area.
A re-run in the affected area has been fixed for January 9.
Kidnapping for ransom, which largely involved foreign oil workers, was rife in the oil-producing Niger delta until a 2009 amnesty significantly reduced unrest in the region.
The victims are usually released after the payment of ransom.